Thursday, March 19, 2015

Influenza B Causes Uncommon Rash in Canadian Outbreak

Influziasts, ProMed has struck my fancy once again. When I think of a list of viral exanthems, certain families come to mind like Paramyxoviridae (Measles), Togaviridae (Rubella), Parvoviridae (B19), Herpesviridae (Roseola, VZV), and Picornaviridae (Hand foot and Mouth). Orthomyxoviridae, the family of Influenza B, was not on this list until today!

Although this came up on the ProMed mailing list today, evidence of the flu associated rash was recorded from an outbreak in March of 2014 in British Columbia, Canada. The study, published in Influenza and Other Respiratory Viruses, found 2 elementary students and 2 high school students presenting with a maculopapular pruritic rash and Influenza like illness.

Maculopapular Pruritic Exanthem in Influenza B Patients

The patients' nasopharyngeal swabs were tested via RT-PCR for presence of influenza and other respiratory viruses. Only Influenza B returned positive. After the first PCR tests, the researchers tested for presence of Measles, enterovirus, and mumps nucleic acids, which all returned negative results. Further testing on the patient's serum was done to analyze antibody IgM titers against Measles, Human Parvovirus B-19, and Rubella. These were also negative.

Although this is an abnormal association in influenza infection, it is not completely novel. The researchers report two previous case associations with exanthem and influenza occurring in one 11 year old from India, and 4 German school children. However, this is the first time that Influenza has been associated with exanthem in North America.